Tremelo all single strings, but leave the power chords as one stroke only.  

Tuning D G C F A D 
Riff 1 
|-------------------------------------------------------------------|
|-------------------------------------------------------------------|
|--------------------------10----------------------------10---------|
|-------------------7-5-7--10-6-------------------7-5-7--10-6--------|
|---7-8-7---7-8-7-5--------8--6---7-8-7---7-8-7-5--------8--6--------|
|-5-------4-------------------4-5-------4-------------------4--------|
  + + + + + + + + + + + +  +  + + + + + + + + + + + + +  + +

Riff 2 cont...
|-------------------------------------------------------------------
|-------------------------------------------------------------------
|-------------------------------------------------------------------
|-7-10-9-7-10-9-7-10-9-7-10-9-6-10-9-6-10-9-6-10-9-6-10-9-----------
|-------------------------------------------------------------------
|-------------------------------------------------------------------
  +  + + +  + + +  + + +  + + +  + + +  + + +  + + +  + +

Riff 2 cont...
|-------------------------------------------------------------------|
|-----------------------------6-9-8-6-9-8-6-9-8-6-9-8---------------|
|-7-10-9-7-10-9-7-10-9-7-10-9---------------------------------------|
|-------------------------------------------------------------------|
|-------------------------------------------------------------------|
|-------------------------------------------------------------------|
  +  + + +  + + +  + + +  + + + + + + + + + + + + + +

Riff 2 cont...
|-------------------------------------------------------------------
|-------------------------------------------------------------------
|-------------------------------------------------------------------
|-7-9-10-7-9-10-7-9-10-7-9-10-6-9-10-6-9-10-6-9-10-6-9-10-----------
|-------------------------------------------------------------------
|-------------------------------------------------------------------
  + +  + + +  + + +  + + +  + + +  + + +  + + +  + + +  +

Riff 2 cont...
|-------------------------------------------------------------------|
|-----------------------------6-8-9-6-8-9-6-8-9-6-8-9---------------|
|-7-9-10-7-9-10-7-9-10-7-9-10---------------------------------------|
|-------------------------------------------------------------------|
|-------------------------------------------------------------------|
|-------------------------------------------------------------------|
  + +  + + +  + + +  + + +  + + + + + + + + + + + + +